The present invention relates generally to electronic faucets. More particularly, the present invention relates to capacitive sensing systems and methods for operating a faucet.
Electronic faucets are often used to control fluid flow. Some electronic faucets include proximity sensors such as active infrared (“IR”) proximity detectors or capacitive proximity sensors to control operation of the faucet. Such proximity sensors are used to detect a user's hands positioned near the faucet and automatically start fluid flow through the faucet in response to detection of the user's hands. Other electronic faucets use touch sensors to control the faucet. Such touch sensors may include capacitive touch sensors or other types of touch sensors located on a spout or on a handle of the faucet for controlling operation of the faucet. Electronic faucets may also include separate touch and proximity sensors.
The present invention uses a single capacitive sensor to provide both touch and hands free modes of operation of the faucet. A user can selectively activate the hands free mode of operation so that the capacitive sensor senses a user's hands in a detection area located near the faucet without requiring the user to touch the faucet. When the hands free mode is activated, the single capacitive sensor detects a user's hands in the detection area and automatically starts fluid flow. The hands free mode may also be selectively disabled.
The use of the capacitive sensor for both touch and proximity sensing eliminates the need for an IR detector and its associated IR detection window. In illustrated embodiments, use of both touch and hands free activation of an electronic faucet provides variable control of water flow for various tasks such as hand-washing, filling a sink, running hot water to purge cold water from the line, or the like. In an illustrated embodiment, both touch and hands free detection is performed with capacitive sensing circuitry connected to the spout with a single wire. A controller of the electronic faucet is programmed with software to evaluate the output signal from the capacitive sensor to determine whether user's hands are detected in the detection area when the proximity sensor is active and to indicate which portion of the faucet is touched and for how long in order to operate the faucet as discussed below.
In an illustrated embodiment of the present disclosure, an electronic faucet comprises a spout having a passageway configured to conduct fluid flow through the spout, an electrically operable valve coupled to the passageway, and a single capacitive sensor coupled to a portion of the faucet. The single capacitive sensor provides both a touch sensor and a proximity sensor for the electronic faucet.
In an illustrated embodiment, the capacitive sensor includes an electrode coupled to the spout. Also in an illustrated embodiment, the electronic faucet further comprises a controller coupled to the capacitive sensor. The controller being configured to monitor an output signal from the capacitive sensor to detect when a portion of the faucet is touched by a user and to detect when a user's hands are located in a detection area located near the spout. The controller is illustratively configured to operate the faucet in either a first mode of operation in which the proximity sensor is inactive or a second mode of operation in which the proximity sensor is active.
In another illustrated embodiment of the present disclosure, a method is provided for controlling fluid flow in an electronic faucet having a spout, a passageway configured to conduct fluid flow through the spout, an electrically operable valve coupled to the passageway, a manual valve located in series with the electrically operable valve, and a manual handle configured to control the manual valve. The illustrated method comprises providing a single capacitive sensor coupled to a portion of the faucet, monitoring an output signal from the capacitive sensor to detect when a user touches at least one of the spout and the manual valve handle and to detect when a user's hands are located in a detection area located near the faucet, and controlling the electrically operable valve is response to the monitoring step.
In an illustrated embodiment, the method further includes providing a first mode of operation of the faucet in which the proximity sensor is inactive, providing a second mode of operation of the faucet in which the proximity sensor is active, and selectively changing between the first and second modes of operation. In one illustrated embodiment, the step of selectively changing between the first and second modes of operation comprises toggling the faucet between the first mode of operation and the second mode of operation in response to detecting a predetermined pattern of touching at least one of the spout and the manual valve handle. In another illustrated embodiment, the step of selectively changing between the first and second modes of operation comprises actuating a mode selector switch.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of an illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.